U.S. patent application number 11/533782 was filed with the patent office on 2008-05-29 for articulating interbody spacer, vertebral body replacement.
Invention is credited to Mahmoud F. Abdelgany.
Application Number | 20080125865 11/533782 |
Document ID | / |
Family ID | 39201148 |
Filed Date | 2008-05-29 |
United States Patent
Application |
20080125865 |
Kind Code |
A1 |
Abdelgany; Mahmoud F. |
May 29, 2008 |
ARTICULATING INTERBODY SPACER, VERTEBRAL BODY REPLACEMENT
Abstract
An interbody spacer implant assembly for interbody fusion in a
vertebral body and a method of insertion comprises a plurality of
links and an elongated connector mechanism adapted to retain the
plurality of links and allow the plurality of links to articulate
with respect to one another. An interbody spacer implant apparatus
for interbody fusion in a vertebral body comprises a plurality of
individually articulating links and a connector mechanism adapted
to retain the plurality of links and allow the plurality of links
to articulate with respect to one another, wherein the connector
mechanism is dimensioned and configured to have a length-to-width
ratio greater than a length-to-width ratio of each of the plurality
of links. The apparatus may further comprise an insertion rod
adapted to insert the plurality of links and the connector
mechanism into the vertebral body.
Inventors: |
Abdelgany; Mahmoud F.;
(Rockaway, NJ) |
Correspondence
Address: |
Gibb & Rahman, LLC
2568-A RIVA ROAD SUITE 304
ANNAPOLIS
MD
21401
US
|
Family ID: |
39201148 |
Appl. No.: |
11/533782 |
Filed: |
September 21, 2006 |
Current U.S.
Class: |
623/17.16 ;
623/17.11 |
Current CPC
Class: |
A61F 2/4425 20130101;
A61F 2220/0033 20130101; A61F 2002/30892 20130101; A61F 2002/30462
20130101; A61F 2220/0075 20130101; A61F 2002/30579 20130101; A61F
2002/30593 20130101; A61F 2/30965 20130101; A61F 2230/0015
20130101; A61F 2/447 20130101; A61F 2002/30538 20130101; A61F
2002/4629 20130101; A61F 2/4611 20130101; A61F 2002/448 20130101;
A61F 2310/00023 20130101; A61F 2002/30354 20130101; A61F 2/4455
20130101; A61F 2220/0091 20130101; A61F 2002/4415 20130101; A61F
2002/30133 20130101; A61F 2002/30471 20130101; A61F 2250/0006
20130101; A61F 2310/00017 20130101 |
Class at
Publication: |
623/17.16 ;
623/17.11 |
International
Class: |
A61F 2/44 20060101
A61F002/44 |
Claims
1. An interbody spacer implant assembly for interbody fusion in a
vertebral body, said assembly comprising: a plurality of links; and
an elongated connector mechanism adapted to retain said plurality
of links and allow said plurality of links to articulate with
respect to one another.
2. The assembly of claim 1, wherein one of said plurality of links
comprises a body portion comprising: partially serrated sides; at
least one first hole configured through a top of said body portion;
a second hole configured through a side of said body portion and
transverse to said at least first hole; a third hole configured
through said body portion and transverse to said second hole; a
fourth hole configured substantially parallel to said at least one
first hole; a connector mechanism positioned transverse to said
partially serrated sides; and a fifth hole configured through said
connector mechanism.
3. The assembly of claim 1, wherein one of said plurality of links
comprises a body portion comprising: serrated sides; at least one
first hole configured through a top of said body portion; a second
hole configured through a side of said body portion and transverse
to said at least first hole; a third hole configured through said
body portion and transverse to said second hole; a pair of
connector flanges positioned transverse to said serrated sides; a
fourth hole configured through each of said pair of connector
flanges; a connector mechanism positioned transverse to said
serrated sides; and a fifth hole configured through said connector
mechanism.
4. The assembly of claim 1, wherein one of said plurality of links
comprises a body portion comprising: serrated sides; at least one
first hole configured through a top of said body portion; a second
hole configured through a side of said body portion and transverse
to said at least first hole; a third hole configured through said
body portion and transverse to said second hole; a pair of
connector flanges positioned transverse to said serrated sides; a
fourth hole configured through each of said pair of connector
flanges; and a fifth hole configured through a rear portion of said
body portion.
5. The assembly of claim 1, further comprising a hinge pin adapted
to connect a first link of said plurality of links to a second link
of said plurality of links.
6. The assembly of claim 1, wherein said elongated connector
mechanism comprises a plurality of pivoting connecting rods
pivotally connected to one another.
7. The assembly of claim 1, wherein one of said plurality of
pivoting connecting rods comprises: a body portion; a peg; and a
hole, wherein said peg and said hole are positioned on opposite
sides of said body portion.
8. The assembly of claim 7, wherein said body portion comprises a
pair of substantially flat side surfaces.
9. The assembly of claim 6, further comprising a retaining pin
adapted to retain said elongated connector mechanism to one of said
plurality of links.
10. The assembly of claim 1, wherein a first link of said plurality
of links is pivotally connected to a second link of said plurality
of links.
11. The assembly of claim 10, wherein said second link of said
plurality of links is pivotally connected to a third link of said
plurality of links.
12. The assembly of claim 1, wherein said elongated connector
mechanism is flexible.
13. The assembly of claim 1, wherein each one of said plurality of
links comprise: a groove; and a hole configured through a side of
said each of said plurality of links.
14. The assembly of claim 13, wherein said elongated connector
mechanism comprises a substantially J-shaped mechanism adapted to
allow said plurality of links to slide thereon.
15. The assembly of claim 1, wherein said plurality of links
comprise a continuous flexible structure.
16. The assembly of claim 1, wherein said connector mechanism is
dimensioned and configured to have a length-to-width ratio greater
than a length-to-width ratio of each of said plurality of
links.
17. An interbody spacer implant apparatus for interbody fusion in a
vertebral body, said apparatus comprising: a plurality of
individually articulating links; and a connector mechanism adapted
to retain the plurality of links and allow said plurality of links
to articulate with respect to one another, wherein said connector
mechanism is dimensioned and configured to have a length-to-width
ratio greater than a length-to-width ratio of each of said
plurality of links.
18. The apparatus of claim 17, further comprising an insertion rod
adapted to insert said plurality of links and said connector
mechanism into said vertebral body.
19. A method of inserting an interbody spacer implant assembly for
interbody fusion into a vertebral body, said method comprising:
connecting an elongated connector mechanism to a plurality of
links; and inserting said elongated connector mechanism and said
plurality of links into said vertebral body, wherein specified ones
of individual links of said plurality of links are adapted to
articulate individually with respect to other individual links upon
insertion into said vertebral body.
20. The method of claim 19, further comprising: attaching an
insertion rod to said elongated connector mechanism; using said
insertion rod to push said elongated connector mechanism and said
plurality of links into said vertebral body; and removing said
insertion rod from said elongated connector mechanism upon full
insertion and final positioning of said elongated connector
mechanism and said plurality of links into said vertebral body.
Description
BACKGROUND
[0001] 1. Technical Field
[0002] The embodiments herein generally relate to medical devices,
and, more particularly, to implantable devices used to stabilize
the human spine.
[0003] 2. Description of the Related Art
[0004] The spinal column is a highly flexible structure comprising
bones and connective tissue. While, the spine is capable of
multiple degrees of motion, spinal injuries or anatomical
irregularities may result in spinal pathologies which limit this
range of motion. Orthopedic surgeons often aim to correct spinal
irregularities and restore stability to traumatized through
immobilization of spinal components.
[0005] Most conventional vertebral spacers and inter body devices
do not provide adequate surface coverage and ease of ideal
positioning, and others are generally too large or bulky to be
inserted in the traditional posterior or transforaminal lumbar
interbody approaches. The conventional large-sized spacers that may
provide this adequate surface coverage typically must be inserted
from an anterior or extreme lateral approach.
[0006] An example of a vertebral spacer is described in U.S. Pat.
Nos. 7,018,413, the complete disclosure of which, in its entirety,
is herein incorporated by reference. Generally, the conventional
designs do not provide the surface coverage and ideal placement
located towards the anterior side of the vertebral endplate while
being implanted through a narrow passageway for transforaminal
lumbar interbody fusion (TLIF) or posterior lumbar interbody fusion
(PLIF) approaches. Generally, surgeons must lightly impact a spacer
laterally towards the medial anterior side, and then try to
position it medially once inside the spinal column to get more even
coverage. Due to nerve anatomy, this can be a difficult task even
for skilled surgeons.
[0007] Accordingly, there remains a need for a new spinal spacer
capable of being properly inserted towards the anterior side of the
vertebral endplate and which can be easily constructed and
ultimately used by a surgeon during a spinal surgical
procedure.
SUMMARY
[0008] In view of the foregoing, an embodiment provides an
interbody spacer implant assembly for interbody fusion in a
vertebral body, wherein the assembly comprises a plurality of links
and an elongated connector mechanism adapted to retain the
plurality of links and allow the plurality of links to articulate
with respect to one another. Preferably, one of the plurality of
links comprises a body portion comprises partially serrated sides;
at least one first hole configured through a top of the body
portion; a second hole configured through a side of the body
portion and transverse to the at least first hole; a third hole
configured through the body portion and transverse to the second
hole; a fourth hole configured substantially parallel to the at
least one first hole; a connector mechanism positioned transverse
to the partially serrated sides; and a fifth hole configured
through the connector mechanism.
[0009] Additionally, one of the plurality of links preferably
comprises a body portion comprising serrated sides; at least one
first hole configured through a top of the body portion; a second
hole configured through a side of the body portion and transverse
to the at least first hole; a third hole configured through the
body portion and transverse to the second hole; a pair of connector
flanges positioned transverse to the serrated sides; a fourth hole
configured through each of the pair of connector flanges; a
connector mechanism positioned transverse to the serrated sides;
and a fifth hole configured through the connector mechanism.
[0010] Moreover, one of the plurality of links may comprise a body
portion comprising serrated sides; at least one first hole
configured through a top of the body portion; a second hole
configured through a side of the body portion and transverse to the
at least first hole; a third hole configured through the body
portion and transverse to the second hole; a pair of connector
flanges positioned transverse to the serrated sides; a fourth hole
configured through each of the pair of connector flanges; and a
fifth hole configured through a rear portion of the body
portion.
[0011] The assembly may further comprise a hinge pin adapted to
connect a first link of the plurality of links to a second link of
the plurality of links. Furthermore, the elongated connector
mechanism preferably comprises a plurality of pivoting connecting
rods pivotally connected to one another. Moreover, one of the
plurality of pivoting connecting rods may comprise a body portion;
a peg; and a hole, wherein the peg and the hole are positioned on
opposite sides of the body portion, wherein the body portion may
comprise a pair of substantially flat side surfaces.
[0012] Additionally, the assembly may further comprise a retaining
pin adapted to retain the elongated connector mechanism to one of
the plurality of links. Preferably, a first link of the plurality
of links is pivotally connected to a second link of the plurality
of links. Also, the second link of the plurality of links is
preferably pivotally connected to a third link of the plurality of
links. Also, the elongated connector mechanism is preferably
flexible. Furthermore, each one of the plurality of links may
comprise a groove and a hole configured through a side of the each
of the plurality of links. Moreover, the elongated connector
mechanism may comprise a substantially J-shaped mechanism adapted
to allow the plurality of links to slide thereon. Additionally, the
plurality of links may comprise a continuous flexible structure.
Preferably, the connector mechanism is dimensioned and configured
to have a length-to-width ratio greater than a length-to-width
ratio of each of the plurality of links.
[0013] Another embodiment provides an interbody spacer implant
apparatus for interbody fusion in a vertebral body, wherein the
apparatus comprises a plurality of individually articulating links
and a connector mechanism adapted to retain the plurality of links
and allow the plurality of links to articulate with respect to one
another, wherein the connector mechanism is dimensioned and
configured to have a length-to-width ratio greater than a
length-to-width ratio of each of the plurality of links. The
apparatus may further comprise an insertion rod adapted to insert
the plurality of links and the connector mechanism into the
vertebral body.
[0014] Another embodiment provides a method of inserting an
interbody spacer implant assembly for interbody fusion into a
vertebral body, wherein the method comprises connecting an
elongated connector mechanism to a plurality of links; and
inserting the elongated connector mechanism and the plurality of
links into the vertebral body, wherein specified ones of individual
links of the plurality of links are adapted to articulate
individually with respect to other individual links upon insertion
into the vertebral body. The method may further comprise attaching
an insertion rod to the elongated connector mechanism; using the
insertion rod to push the elongated connector mechanism and the
plurality of links into the vertebral body; and removing the
insertion rod from the elongated connector mechanism upon full
insertion and final positioning of the elongated connector
mechanism and the plurality of links into the vertebral body.
[0015] These and other aspects of the embodiments herein will be
better appreciated and understood when considered in conjunction
with the following description and the accompanying drawings. It
should be understood, however, that the following descriptions,
while indicating preferred embodiments and numerous specific
details thereof, are given by way of illustration and not of
limitation. Many changes and modifications may be made within the
scope of the embodiments herein without departing from the spirit
thereof, and the embodiments herein include all such
modifications.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The embodiments herein will be better understood from the
following detailed description with reference to the drawings, in
which:
[0017] FIG. 1(A) illustrates an exploded schematic diagram of an
articulating interbody spacer apparatus according to an embodiment
herein;
[0018] FIGS. 1(B) through 1(G) illustrate schematic diagrams of the
articulating interbody spacer apparatus of FIG. 1(A) according to
an embodiment herein;
[0019] FIG. 2 illustrates a schematic diagram of an articulating
interbody spacer assembly according to an embodiment herein;
[0020] FIGS. 3(A) through 3(C) illustrate schematic diagrams of the
retaining pin of the articulating interbody spacer apparatus of
FIGS. 1(A) through 1(G) according to an embodiment herein;
[0021] FIGS. 4(A) through 4(F) illustrate schematic diagrams of the
first hinged rod of the articulating interbody spacer apparatus of
FIGS. 1(A) through 1(G) according to an embodiment herein;
[0022] FIGS. 5(A) through 5(F) illustrate schematic diagrams of the
second hinged rod of the articulating interbody spacer apparatus of
FIGS. 1(A) through 1(G) according to an embodiment herein;
[0023] FIGS. 6(A) through 6(F) illustrate schematic diagrams of the
third hinged rod of the articulating interbody spacer apparatus of
FIGS. 1(A) through 1(G) according to an embodiment herein;
[0024] FIGS. 7(A) through 7(F) illustrate schematic diagrams of the
insertion rod of the articulating interbody spacer apparatus of
FIGS. 1(A) through 1(G) according to an embodiment herein;
[0025] FIGS. 8(A) through 8(F) illustrate schematic diagrams of the
first link of the articulating interbody spacer apparatus of FIGS.
1(A) through 1(G) according to an embodiment herein;
[0026] FIGS. 9(A) through 9(C) illustrate schematic diagrams of the
hinge pin of the articulating interbody spacer apparatus of FIGS.
1(A) through 1(G) according to an embodiment herein;
[0027] FIGS. 10(A) through 10(F) illustrate schematic diagrams of
the second link of the articulating interbody spacer apparatus of
FIGS. 1(A) through 1(G) according to an embodiment herein;
[0028] FIGS. 11(A) through 11(F) illustrate schematic diagrams of
the third link of the articulating interbody spacer apparatus of
FIGS. 1(A) through 1(G) according to an embodiment herein;
[0029] FIGS. 12(A) through 12(F) are schematic diagrams
illustrating subsequent stages of insertion of the articulating
interbody spacer assembly of FIG. 2 into a vertebral body according
to an embodiment herein;
[0030] FIG. 13 is a schematic diagram of a first alternate
embodiment of an articulating interbody spacer assembly according
to the embodiments herein;
[0031] FIGS. 14(A) through 14(C) are schematic diagrams of a second
alternate embodiment of an articulating interbody spacer assembly
according to the embodiments herein;
[0032] FIGS. 15(A) and 15(B) are schematic diagrams of a third
alternate embodiment of an articulating interbody spacer assembly
according to the embodiments herein;
[0033] FIGS. 16(A) and 16(B) are schematic diagrams of a fourth
alternate embodiment of an articulating interbody spacer assembly
according to the embodiments herein; and
[0034] FIG. 17 is a flow diagram illustrating a preferred method
according to an embodiment herein.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0035] The embodiments herein and the various features and
advantageous details thereof are explained more fully with
reference to the non-limiting embodiments that are illustrated in
the accompanying drawings and detailed in the following
description. Descriptions of well-known components and processing
techniques are omitted so as to not unnecessarily obscure the
embodiments herein. The examples used herein are intended merely to
facilitate an understanding of ways in which the embodiments herein
may be practiced and to further enable those of skill in the art to
practice the embodiments herein. Accordingly, the examples should
not be construed as limiting the scope of the embodiments
herein.
[0036] As mentioned, there remains a need for a new spinal spacer
capable of being properly inserted towards the anterior side of the
vertebral endplate and which can be easily constructed and
ultimately used by a surgeon during a spinal surgical procedure.
The embodiments herein achieve this by providing an articulating
interbody spacer that is dimensioned and configured to be inserted
through a proportionately narrow passageway and which provides
optimal surface coverage and placement, thereby reducing the
chances of subsidence into the vertebral endplates. Referring now
to the drawings, and more particularly to FIGS. 1(A) through 17,
where similar reference characters denote corresponding features
consistently throughout the figures, there are shown preferred
embodiments.
[0037] FIGS. 1(A) through 1(G) illustrate various views of an
articulating interbody spacer apparatus 100 according to an
embodiment herein. Generally, the apparatus 100 comprises a
retaining pin 1, a first hinged rod 2, a second hinged rod 3, a
third hinged rod 4, an insertion rod 5, a first link 6, a second
link 8, third link 9, and a plurality of hinge pins 7. One of the
hinge pins 7 is used to connect the first link 6 to the second link
8, while the other hinge pin 7 is used to connect the second link 8
to the third link 9. Moreover, the first hinged rod 2 is adapted to
connect to the second hinged rod 3, and the second hinged rod 3 is
adapted to connect to the third hinged rod 4. The retaining pin 1
is adapted to securely connect the first hinged rod 2 to the first
link 6, and the insertion rod 5 is adapted to connect to the third
hinged rod 4, whereby the insertion rod 5 is adapted to be
disconnected from the third hinged rod 4.
[0038] FIG. 2 illustrates a schematic diagram of an articulating
interbody spacer assembly 101 according to an embodiment herein.
The difference between the assembly 101 of FIG. 2 and the apparatus
of FIGS. 1(A) through 1(G) is that the assembly 101 does not
include the insertion rod 5 (i.e., after the insertion rod 5 has
been disconnected from the third hinged rod 4). As FIG. 2
illustrates, the first link 6, second link 8, and third link 9 are
pivotally connected to one another in the manner described above by
using the hinge pins 7 for the various connections (i.e.,
connection of the first link 6 to the second link 8 and the
connection of the second link 8 to the third link 9), and as such
allows the assembly 101 to articulate from a generally straight
position to a generally curved position.
[0039] FIGS. 3(A) through 3(C) illustrate schematic diagrams of the
retaining pin 1 of the articulating interbody spacer apparatus 100
of FIGS. 1(A) through 1(G) according to an embodiment herein. The
retaining pin 1 comprises a shaft 11 with a cap portion 13
positioned on top of the shaft 11. Moreover, the cap portion 13 has
an exposed under surface 12 such that the circumferential
configuration of the cap portion 13 is preferably larger than the
circumferential configuration of the shaft 11.
[0040] FIGS. 4(A) through 4(F) illustrate schematic diagrams of the
first hinged rod 2 of the articulating interbody spacer apparatus
100 of FIGS. 1(A) through 1(G) according to an embodiment herein.
The first hinged rod 2 is generally embodied in an elongated
configuration. The first hinged rod 2 comprises an elongated body
portion 15 that is generally rounded terminating in a pair of ends
16, 17 opposed from one another. The first end 17 of the body
portion 15 is defined by an upper generally flat base 20 bounded by
a generally sloping wall 21. A pivot peg 19 outwardly extends from
the flat base 20 in a generally perpendicular manner. The upper
surface of the flat base 20 is positioned below the upper surface
of the body portion 15 such that the upper surface of the pivot peg
19 may be substantially planar to the upper surface of the body
portion 15. The second end 16 of the body portion 15 comprises a
retention hole 18 configured substantially transverse to the
longitudinal axis of the body portion 15.
[0041] FIGS. 5(A) through 5(F) illustrate schematic diagrams of the
second hinged rod 3 of the articulating interbody spacer apparatus
100 of FIGS. 1(A) through 1(G) according to an embodiment herein.
The second hinged rod 3 is generally embodied in an elongated
configuration and comprises two generally rounded longitudinal
sides 32 and two substantially flat sides 30. The flat sides 30
allow for flexion in the needed direction during articulation of
the second hinged rod 3. A pair of ends 33, 34 opposed from one
another is also provided on the second hinged rod 3. The first end
34 is defined by an upper generally flat base 37 bounded by a
generally sloping wall 36. A pivot peg 35 outwardly extends from
the flat base 37 in a generally perpendicular manner. The upper
surface of the flat base 37 is positioned below the upper surface
of the top generally rounded longitudinal side 32 such that the
upper surface of the pivot peg 35 may be substantially planar to
the upper surface of the top generally rounded longitudinal side
32. The second end 33 comprises a generally flat upper surface 39
bounded by a generally sloping wall 38. The second end 33 further
includes a pivot hole 31 configured substantially transverse to the
longitudinal axis of the two generally rounded longitudinal sides
32 and two substantially flat sides 30.
[0042] FIGS. 6(A) through 6(F) illustrate schematic diagrams of the
third hinged rod 4 of the articulating interbody spacer apparatus
100 of FIGS. 1(A) through 1(G) according to an embodiment herein.
The third hinged rod 4 is generally embodied in an opposite
configuration of the second hinged rod 3. The third hinged rod 4
also comprises a generally elongated configuration and includes two
generally rounded longitudinal sides 46 and two substantially flat
sides 40. The flat sides 40 allow for flexion in the needed
direction during articulation of the third hinged rod 4. A pair of
ends 41, 42 opposed from one another is also provided on the third
hinged rod 4. The first end 42 comprises a generally flat upper
surface 44 bounded by a generally sloping wall 47. The first end 42
further includes a pivot hole 43 configured substantially
transverse to the longitudinal axis of the two generally rounded
longitudinal sides 46 and two substantially flat sides 40. The
second end 41 is defined by an upper generally flat base 49 bounded
by a generally sloping wall 48. A pivot peg 45 outwardly extends
from the flat base 49 in a generally perpendicular manner. The
upper surface of the flat base 49 is positioned below the upper
surface of the top generally rounded longitudinal side 46 such that
the upper surface of the pivot peg 45 may be substantially planar
to the upper surface of the top generally rounded longitudinal side
46.
[0043] FIGS. 7(A) through 7(F) illustrate schematic diagrams of the
insertion rod 5 of the articulating interbody spacer apparatus 100
of FIGS. 1(A) through 1(G) according to an embodiment herein. The
insertion rod 5 is generally embodied in an elongated
configuration. The insertion rod 5 comprises an elongated body
portion 51 that is generally rounded terminating in a pair of ends
52, 53 opposed from one another. The first end 52 of the body
portion 51 is defined by an upper generally flat base 55 bounded by
a generally sloping wall 56. The upper surface of the flat base 55
is positioned below the upper surface of the body portion 51. The
first end 52 further comprises a pivot hole 54 configured
substantially transverse to the longitudinal axis of the body
portion 51. The second end 53 is adapted to be attached to an
inserter tool/mechanism (not shown).
[0044] FIGS. 8(A) through 8(F) illustrate schematic diagrams of the
first link 6 of the articulating interbody spacer apparatus 100 of
FIGS. 1(A) through 1(G) according to an embodiment herein. The
first link 6 comprises a body portion 71 having a top end 77 and a
bottom end 78, whereby the top end 77 is configured with a pair of
vertical bone graft windows 62 that are adapted to allow for bone
growth during fusion. The body portion 71 of the first link 6 also
comprises a pair of opposed partially serrated sides 61 each
terminating with unserrated tapered walls 63 towards a front end 72
of the body portion 71. The top end 77 terminates with a downwardly
sloping wall 79 towards the front end 72. Moreover, the bottom end
78 terminates with an upwardly sloping wall 179 towards the front
end 72. The back end of the body portion 71 comprises a generally
sloping wall 70 having a connector mechanism 69 extending
therefrom. The connector mechanism 69 has generally flat side
surfaces 68 and a throughhole 65 configured transversely with
respect to the longitudinal axis of the body portion 71. A rod
retention hole 67 extends from the sloping wall 70 at the rear of
the body portion 71 through to the sloping wall 79 at the front of
the body portion 71. Additionally, the rod retention hole 67
extends through the upper part of the body portion 71 along a
substantially longitudinal axis of the body portion 71 and is
dimensioned and configured to accommodate the first hinged rod 2 of
the apparatus 100 of FIGS. 1(A) through 1(G). Also, configured in
the upwardly sloping wall 179 is a retention pin hole 66, which is
dimensioned and configured to accommodate the retaining pin 1 of
the apparatus 100 of FIGS. 1(A) through 1(G). A horizontal bone
graft window 64 is positioned in the generally central part of the
body portion 71 and is configured to be substantially transverse to
the longitudinal axis of the body portion 71. In other words, the
horizontal bone graft window 64 and the throughhole 65 are
substantially parallel to one another.
[0045] FIGS. 9(A) through 9(C) illustrate schematic diagrams of the
hinge pin 7 of the articulating interbody spacer apparatus 100 of
FIGS. 1(A) through 1(G) according to an embodiment herein. The
hinge pin 7 is generally configured in a cylindrical embodiment,
although other configurations may be used in accordance with the
embodiments herein. The hinge pin 7 comprises a shaft 75
terminating in a pair of ends 76a, 76b.
[0046] FIGS. 10(A) through 10(F) illustrate schematic diagrams of
the second link 8 of the articulating interbody spacer apparatus
100 of FIGS. 1(A) through 1(G) according to an embodiment herein.
The second link 8 comprises a body portion 81 having a top end 82
and a bottom end 83, whereby the top end 82 is configured with a
pair of vertical bone graft windows 122 that are adapted to allow
for bone growth during fusion. The body portion 81 of the second
link 8 also comprises a pair of opposed serrated sides 88. The top
end 82 terminates with a downwardly sloping wall 186, which then
terminates with a further downwardly sloping wall 84 sandwiched in
between a pair of connector flanges 85. Each connector flange 85
comprises a throughhole 120 aligned with one another. The rear of
the body portion 81 comprises a generally sloping wall 86 having a
connector mechanism 87 extending therefrom. The connector mechanism
87 has generally flat side surfaces 124 and a throughhole 121
configured transversely with respect to the longitudinal axis of
the body portion 81. A rod retention hole 89 extends from the
sloping wall 86 at the rear of the body portion 81 through to the
sloping wall 186 at the front of the body portion 81. Additionally,
the rod retention hole 89 extends through the upper part of the
body portion 81 along a substantially longitudinal axis of the body
portion 81 and is dimensioned and configured to accommodate
portions of the second hinged rod 3 and third hinged rod 4 of the
apparatus 100 of FIGS. 1(A) through 1(G). A horizontal bone graft
window 123 is positioned in the generally central part of the body
portion 81 and is configured to be substantially transverse to the
longitudinal axis of the body portion 81. In other words, the
horizontal bone graft window 123 and the throughhole 121 are
substantially parallel to one another.
[0047] FIGS. 11(A) through 11(F) illustrate schematic diagrams of
the third link 9 of the articulating interbody spacer apparatus 100
of FIGS. 1(A) through 1(G) according to an embodiment herein. The
third link 9 comprises a body portion 91 having a top end 92 and a
bottom end 93, whereby the top end 92 is configured with a pair of
vertical bone graft windows 99 that are adapted to allow for bone
growth during fusion. The body portion 91 of the third link 9 also
comprises a pair of opposed serrated sides 98. The top end 92
terminates with a downwardly sloping wall 188, which then
terminates with a further downwardly sloping wall 94 sandwiched in
between a pair of connector flanges 95. Each connector flange 95
comprises a throughhole 130 aligned with one another. A rod
retention hole 97 extends from the rear wall 96 of the body portion
91 through to the sloping wall 188 at the front of the body portion
91. Additionally, the rod retention hole 97 extends through the
upper part of the body portion 91 along a substantially
longitudinal axis of the body portion 91 and is dimensioned and
configured to accommodate portions of the second hinged rod 3, the
third hinged rod 4, and the insertion rod 5 of the apparatus 100 of
FIGS. 1(A) through 1(G). A horizontal bone graft window 132 is
positioned in the generally central part of the body portion 91 and
is configured to be substantially transverse to the longitudinal
axis of the body portion 91. Accordingly, the horizontal bone graft
window 132 and the throughhole 130 are substantially parallel to
one another. A threaded hole 131 extends through the lower part of
the body portion 91 along a substantially longitudinal axis of the
body portion 91 and has its opening at the rear wall 96.
Preferably, threaded hole 131 is positioned off axis directed
towards the top end 92 to keep the implant assembly 101 from
articulating prematurely during impaction. Furthermore, rear wall
96 is preferably perpendicular to threaded hole 131 for the same
reason.
[0048] FIGS. 12(A) through 12(F) are schematic diagrams
illustrating subsequent stages of insertion of the articulating
interbody spacer assembly 101 of FIG. 2 into a vertebral body 200
according to an embodiment herein. In practice, the assembly 101
will be inserted using the insertion rod 5. In the first stage of
insertion shown in FIG. 12(A), the assembly 101 is in a generally
straight configuration and is inserted into a previously drilled
opening in the vertebral body 200. In the second stage of insertion
shown in FIG. 12(B), the assembly 101 is still in a generally
straight configuration and is nearly entirely inside the vertebral
body 200. In the third stage of insertion shown in FIG. 12(C), the
assembly 101 begins to articulate such that the first link 6 begins
to pivot. In the fourth stage of insertion shown in FIG. 12(D), the
assembly 101 is entirely within the vertebral body 200 with the
first link 6 in its pivoted position. In the fifth stage of
insertion shown in FIG. 12(E), the assembly 101 is entirely within
the vertebral body 200 with each of the first, second, and third
links 6, 8, 9 being in their respective pivoted positions. In the
sixth stage of insertion shown in FIG. 12(F), the assembly 101 is
in its final position of insertion (i.e., resting position) with
each of the first, second, and third links 6, 8, 9 being in their
respective pivoted positions.
[0049] FIG. 13 is a schematic diagram of a first alternate
embodiment of an articulating interbody spacer assembly 204
according to the embodiments herein. FIG. 13 illustrates the
assembly in its initial position 250 as well as its articulated
final position 251 within a vertebral body 200. In this embodiment
(also referred to as a living hinge embodiment) the hinged links
306 of the implant are made of a single piece flexible material
held together by a cable or guide wire 205 as opposed to having
separate links 6, 8, 9 pivoting off a hinge pin 7.
[0050] FIGS. 14(A) through 14(C) are schematic diagrams of a second
alternate embodiment of an articulating interbody spacer assembly
304 according to the embodiments herein. This assembly 304
comprises links 306 connected by a flexible (living) hinge 307.
Connection rivets 308 are used to attach the flexible hinge 307 to
the links 306. The flexible hinge 307 is made of a separate
material (with respect to the links 306) and is securely attached
to the links 306 with proper spacing so that the links 306 can
articulate to provide the desired articulating result. The flexible
hinge 307 may comprise implantable stainless steel, titanium alloy,
or nitinol. Moreover, the links 306 may comprise carbon fiber, PEEK
optima, or titanium.
[0051] FIGS. 15(A) and 15(B) are schematic diagrams of a third
alternate embodiment of an articulating interbody spacer assembly
201 according to the embodiments herein. This assembly 201 is
similar to the assembly 101 of FIG. 2 except the first, second, and
third hinged rods 2, 3, 4 of assembly 101 are replaced with a
single cable or guide wire 205 that is allowed to flex or bend
where the first, second, and third hinged links 6, 8, 9
respectively articulate.
[0052] FIGS. 16(A) and 16(B) are schematic diagrams of a fourth
alternate embodiment of an articulating interbody spacer assembly
301 according to the embodiments herein. The assembly 301 comprises
an implantable ramp 305 comprising an initially open end 309 and
terminating with a closed end 310. The ramp 305 is initially
inserted between two vertebral bodies upon which the links 406 may
slide down (terminating at the closed end 310) for optimal
placement. The links 406 comprise a groove 312 to allow the links
406 to slide on the ramp 305. The ramp 305 then becomes part of the
permanent implant assembly 301. The links 406 are not connected to
one another, thus gaps 311 exist until the links 406 come to rest
next to one another. After insertion, the open end 309 may be
appropriately bent or configured to prevent the links 406 from
coming off of the ramp 305.
[0053] With respect to FIGS. 1(A) through 16(B), the apparatus 100
may be assembled as follows: the first, second, and third links 6,
8, 9 are assembled together in succession using hinge pins 7 to
connect the first link 6 to the second link 8, and the second link
8 to the third link 9. Specifically, the connector mechanism 69 of
the first link 6 is inserted between the pair of connector flanges
85 of the second link 8 such that the throughhole 65 of the
connector mechanism 69 is aligned with each of the throughholes 120
of the pair of connector flanges 85. The flat side surfaces 68 of
the connector mechanism 69 are dimensioned and configured to
provide a frictional fit with the pair of connector flanges 85 of
the second link 8 so the implant assembly 101 will not buckle or
articulate prematurely upon impaction. Similarly, the pair of
connector flanges 85 are dimensioned and configured to provide a
frictional fit with the flat side surfaces 68 of the connector
mechanism 69 so the implant assembly 101 will not buckle or
articulate prematurely upon impaction. Once the throughholes 65,
120 are aligned, a hinge pin 7 is inserted therein to rotatably
attach the first link 6 to the second link 8. The hinge pin 7
allows for a pivot axis of the first link 6 and the second link 8
during the insertion stages (shown in FIGS. 12(A) through 12(F)).
After this, the connector mechanism 87 of the second link 8 is
inserted between the pair of connector flanges 95 of the third link
9 such that the throughhole 121 of the connector mechanism 87 is
aligned with each of the throughholes 130 of the pair of connector
flanges 95. The flat side surfaces 124 of the connector mechanism
87 are dimensioned and configured to provide a frictional fit with
the pair of connector flanges 95 of the third link 9 so the implant
assembly 101 will not buckle or articulate prematurely upon
impaction. Similarly, the pair of connector flanges 95 are
dimensioned and configured to provide a frictional fit with the
flat side surfaces 124 of the connector mechanism 87. Once the
throughholes 121, 130 are aligned, a hinge pin 7 is inserted
therein to rotatably attach the second link 8 to the third link
9.
[0054] Next, pivot peg 19 of the first hinged rod 2 is connected to
pivot hole 31 of the second hinged rod 3. Then, pivot peg 35 of the
second hinged rod 3 is connected to pivot hole 43 of the third
hinged rod 4. After this, pivot peg 45 of the third hinged rod 4 is
connected to pivot hole 54 of the insertion rod 5 and the assembled
rods 2, 3, 4, 5 are inserted into the connected first, second, and
third links 6, 8, 9. Finally, the retaining pin 1 is press fit into
retention pin hole 66 of first link 6 and captures the retention
hole 18 of the first hinged rod 2. More specifically, the exposed
under surface 12 of retaining pin 1 is flush seated in retention
pin hole 66 of first link 6. The second end 53 of the insertion rod
5 is adapted to be attached to an inserter tool/mechanism (not
shown). Again, the insertion rod 5 does not get implanted in the
vertebral body 200. Rather, the insertion rod 5 is removed once the
implant assembly 101 is fully articulated in its final
position.
[0055] The implant assembly 101 comprises various structural
features, which provides it with enhanced functionality. For
example, with respect to the first link 6, the serrated sides 61
provide friction and avoid dislocation after the assembly 101 is
implanted in the vertebral body 200. Moreover, the tapered walls 63
allow for the structural distraction of adjacent vertebral bodies
during insertion of the assembly 101 into the vertebral body 200.
Additionally, the horizontal bone graft window 64 allows for bone
packing prior to assembly 101 implantation in the vertebral body
200. Also, the rod retention hole 67 is adapted to accommodate the
first hinged rod 2.
[0056] With respect to the second link 8, the serrated sides 88
provide friction and avoid dislocation after the assembly 101 is
implanted in the vertebral body 200. Additionally, the horizontal
bone graft window 123 allows for bone packing prior to assembly 101
implantation in the vertebral body 200. Also, the rod retention
hole 89 is adapted to accommodate the first, second, and third
hinged rods 2, 3, 4 during insertion of the connected rods 2, 3, 4,
5 during assembly of the apparatus 100. With respect to the third
link 9, the serrated sides 98 provide friction and avoid
dislocation after the assembly 101 is implanted in the vertebral
body 200. Additionally, the horizontal bone graft window 132 allows
for bone packing prior to assembly 101 implantation in the
vertebral body 200. Also, the rod retention hole 97 is adapted to
accommodate the first, second, and third hinged rods 2, 3, 4 and
the insertion rod 5 during insertion of the connected rods 2, 3, 4,
5 during assembly of the apparatus 100. Moreover, the threaded hole
131 is adapted to connect with an inserter tool/mechanism (not
shown) during implantation of the assembly 101 into a vertebral
body 200. This connection is temporary as both the insertion rod 5
and the inserter tool/mechanism (not shown) are removed once the
implant assembly 101 is fully articulated in its final position in
the vertebral body 200. This is possible because the rod retention
hole 97 is properly sized to allow release of the insertion rod 5
and the inserter tool/mechanism (not shown) once full articulation
and final positioning of the assembly 101 is achieved in the
vertebral body 200.
[0057] As mentioned, the implant assembly 101 is preferably
attached to and inserted or impacted by insertion means such as an
inserter tool/mechanism (not shown). In a preferred mode, the
inserter tool/mechanism (not shown) may comprise of a shaft of an
appropriate length. On one end may comprise a protrusion that is
attached to the third link 9 via a thread, a snap fitting, or
simply a friction fit stud. On the opposite end, the inserter
tool/mechanism (not shown) may comprise a handle with an impact
surface. The handle may also comprise a mechanism(s) to pull or
push on the insertion rod 5 to articulate the implant assembly 101
during insertion into a vertebral body 200. When the implant-loaded
inserter is lightly impacted, the implant assembly 101 is wedged
between two vertebral bodies to slightly distract them (by means of
tapered walls 63 of the first link 6) while being impacted with
sufficient force to overcome the friction between the two bone
surfaces.
[0058] As the implant assembly 101 is advanced into the spine, the
surgeon may activate the mechanism(s) on the inserter
tool/mechanism (not shown) to "bend" or articulate the implant
assembly 101 until it is implanted in its final position (as shown
in FIGS. 12(A) through 12(F)). Once the implant assembly 101 is
fully articulated in its final position, the insertion rod 5 is
allowed to disassemble from the implant assembly 101 by sliding the
insertion rod 5 up or down towards the vertebral body 200. After
the removal of the insertion rod 5, the inserter tool/mechanism
(not shown) is also removed from the implant assembly 101.
[0059] FIG. 17, with reference to FIGS. 1(A) through 16(B), is a
flow diagram illustrating a method of inserting an interbody spacer
implant assembly 101 for interbody fusion into a vertebral body 200
according to an embodiment herein, wherein the method comprises
connecting (501) an elongated connector mechanism (rods 2, 3, 4 or
wire 205 or ramp 305 or flexible hinge 307) to a plurality of links
(6, 8, 9, 306, 406); and inserting (503) the elongated connector
mechanism (rods 2, 3, 4 or wire 205 or ramp 305 or flexible hinge
307) and the plurality of links (6, 8, 9, 306, 406) into the
vertebral body 200, wherein specified ones of individual links 6,
8, 306, 406 of the plurality of links (6, 8, 9, 306, 406) are
adapted to articulate individually with respect to other individual
links 6, 8, 9, 306, 406 upon insertion into the vertebral body 200.
The method may further comprise attaching an insertion rod 5 to the
elongated connector mechanism (rods 2, 3, 4); using the insertion
rod 5 to push the elongated connector mechanism (rods 2, 3, 4) and
the plurality of links 6, 8, 9 into the vertebral body 200; and
removing the insertion rod 5 from the elongated connector mechanism
(rods 2, 3, 4) upon full insertion and final positioning of the
elongated connector mechanism (rods 2, 3, 4) and the plurality of
links 6, 8, 9 into the vertebral body 200.
[0060] The implant assembly 101 generally comprises a plurality of
links 6, 8, 9 that are hinged together in one plane and at least
one pivoting rod 2, 3, 4 (or some other connecting mechanism 205,
305, 307) assembled through the links 6, 8, 9 (or 306, 406) which
are allowed to translate axially. These pivoting rods 2, 3, 4 (or
some other connecting mechanism 205, 305, 307) function to pull or
push on the hinged links 6, 8, 9 (or 306, 406) to articulate them
into a desired shape during implantation. The pivoting rods 2, 3, 4
(or some other connecting mechanism 205, 305, 307) are configured
to have a greater length-to-width ratio than the length-to-width
ratio of each one of the individual links 6, 8, 9 (or 306, 406).
The links 6, 8, 9 (or 306, 406) preferably only articulate one at a
time sequentially, starting with the first link 6 and ending with
the second link 8. More specifically, the third link 9 does not
articulate; only the first link 6 and second link 8 articulate with
reference to the third link 9 as shown in FIGS. 12(A) through
12(F). This constrained motion is due to the pivoting rods 2, 3, 4
(or some other connecting mechanism 205, 305, 307) only being able
to articulate past the hinged link segments. The geometry of the
pivoting rods 2, 3, 4 (or some other connecting mechanism 205, 305,
307) is constrained while inside the respective links 6, 8, 9 (or
306, 406) and cannot articulate until the previous link is in its
fully articulated state. Once links 6, 8 (or 306) are fully
articulated, only then can the insertion pivoting rod 2, 3, 4 (or
some other connecting mechanism 205, 305, 307) be allowed to slide
in the hinged portion (i.e., pivot peg 45) and dissemble from the
implant assembly 101.
[0061] The embodiments herein may be utilized in surgery to
stabilize the human spine. It may be used to replace a human disc
that is no longer functioning properly and restore height between
to vertebral bodies, or used to as a full or partial vertebral body
replacement device. Preferably, the embodiments herein may be used
with some form of the many available fixation devices either from a
posterior, anterior, or lateral approach. Moreover, the embodiments
herein provide an improvement over conventional devices in terms of
the structure of the device, the method of implantation, and
patient stability after implantation. The embodiments herein are
dimensioned and configured to be manufactured from any appropriate
implantable material(s) and may utilize all the standard surgical
tools that accompany such devices.
[0062] The foregoing description of the specific embodiments will
so fully reveal the general nature of the embodiments herein that
others can, by applying current knowledge, readily modify and/or
adapt for various applications such specific embodiments without
departing from the generic concept, and, therefore, such
adaptations and modifications should and are intended to be
comprehended within the meaning and range of equivalents of the
disclosed embodiments. It is to be understood that the phraseology
or terminology employed herein is for the purpose of description
and not of limitation. Therefore, while the embodiments herein have
been described in terms of preferred embodiments, those skilled in
the art will recognize that the embodiments herein can be practiced
with modification within the spirit and scope of the appended
claims.
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